The present invention relates generally to wireless communication networks and, in particular, to network elements for attending a user""s mobile-terminal equipment.
Communication services are provided to users"" mobile-terminal equipment (UE) by wireless communication networks. The wireless communication network provides communication services to a particular UE is referred to as a serving network that with respect to that UE. Before a UE can avail itself of the services provided by any wireless communication network, the UE must become attached to a wireless communication network. Upon attaching, the UE enters a call send/receive state by registering with its serving network to send/receive calls in real-time. In the call send/receive state, the UE is attended by a network element. The particular network element attending the UE is called a Serving Call State Control Function (S-CSCF) or a Serving Session Management Function (S-SMF) in specifications defined by the well-known 3GPP and 3GPP2 partnership projects, respectively. For purposes of this application, the attending network element will hereinafter be referred to as an xe2x80x9cactive service attendant.xe2x80x9d The active service attendant provides all functionalities necessary for controlling and managing all incoming/outgoing calls to/from the UE, and ensures invocation of all applicable service subscriptions of the UE.
UEs unattached to and unregistered with a serving network are not attended by an active service attendant for sending/receiving calls. Calls to unattached/unregistered UEs are greeted by an unavailability announcement of sort indicating that the called party is unavailable. For example, the unavailability announcement states that xe2x80x9cthe person you are trying to reach is unavailable at this timexe2x80x9d or xe2x80x9cplease leave a message.xe2x80x9d Typically, it is the wireless communication network service provider""s choice as to which unavailability announcement is used.
When a UE is unattached or unregistered, some or all services subscribed to by the associated user may not be invoked. For example, calls to users with call forwarding service subscriptions may not be forwarded if the associated UEs are unattached or unregistered. Accordingly, there exist a need for ensuring invocation of all or some services subscribed to by users of unattached or unregistered UEs.
The present invention is a surrogate service attendant for ensuring invocation of services subscribed to by users of mobile-terminal equipment which are unattached or unregistered. When a call for an unattached/unregistered user mobile-telephone equipment (UE) is received by a wireless communication network, the surrogate service attendant will ensure invocation of the user""s service subscriptions according to a set of service handling instructions. In one embodiment, the service handling instructions are issued by an application server, which is operable to execute service logic programs for various value added services.